Core drill



2 Sheets-Sheet l 5 4 3 3 4 w 7 m H ma w fly m mm W 2 NF Nov. 30, 1937.A. c. CATLAND CORE DRILL Filed April I, 1935 Nov. 30, 1937. A. c.CATLAND CORE DRILL Filed April 1, 1955 2 Sheets-Sheet 2 H a a 7 "a 3$2.7 4 E /.3W& x flaw? 0 2 c 8- w a wwx W T x h a a a. y a x m@ C. E V0NE W A ,4 TTOE/VEV Patented Nov. 30, 1937 UNITED STATES PATENT OFFICEcons mum.

Application April 1, 1935, Serial No. 14,120

16 Claims.

This invention relates to a well drilling tool and relates moreparticularly to a rotary well core drill. A general object of thisinvention is to provide a practical effective core drill embodying animproved and particularly efiicient core catching means or corerecovering means.

Considerable diificulty has been "encountered in providing dog typecorecatchers with dog actuating springs of the proper tension or strength.When the springs are too strong the dogs are pressed against theentering core with considerable force and destroy the core during thecoring or drilling operation. On the other hand, when the core actuatingsprings are not of the required strength they do not provide for theproper operation or functioning of the dogs. Core catchers have beenintroduced in which the dogs or gripping parts are actuated by fluidpressure but difficulty is sometimes encountered in applying the properfluid pressures for the different types of tool structures and earthformations.

Another object of this invention is to provide a core drill embodying acore recovering means in which the core gripping parts are dependablylatched in retracted positions free of the core during thedrilling'operation and may be readily released when desired to bepositively actuated by an actuating means or control that insures theirfull effective operation.

Another object of the invention is to provide a core drill of thecharacter mentioned in which the core catching means may be actuatedwithout manipulating the drilling string and without special orcomplicated control of the circulation fluid. Another object of theinvention is to provide a core catcher that is adapted to obtain a fullsized unmutilated core. Another object of the invention is to provide acore drill in which the several core gripping and retaining dogs areoperated by springs under the control of a novel latch. The dogactuating springs are normally held inoperative so that they do not urgethe dogs against the core and, therefore, may be as strong as desired.

Another object of the invention is to provide a novel particularlyeffective core catcher comprising pivoted spring actuated dogs and a doglatching sleeve having gripping slips that aid the dogs in brealh'nghard cores free from the formation and in retaining the freed cores.

Another object of the invention is to provide a core drill of thecharacter mentioned that does not interfere with the free flow of thecirculation fluid during the drilling operation or during the recoveryof the core- Another object of the invention is to provide a core drillthat includes a core catching or core recovering means that does notengage the core or interfere with the passage of the core into the drillduring the drilling operation and that may be easily controlled orreleased for actuation from the well derrick.

The various objects and features of my invention will be fullyunderstood from the following detailed description of a typicalpreferred form and application of the invention, throughout whichdescription reference ismade to the accompanying drawings, in which:

Fig. 1 is a side elevation of the drill provided by this invention, withthe principal parts broken away to appear in vertical cross sectionshowing the parts in the unactuated positions. Fig. 2 is an enlargedfragmentary longitudinal sectional view of the upper portion of thedrill illustrating the inner barrel suspending means in a releasedcondition. Fig. 3 is a transverse detailed sectional view takensubstantially as indicated by line 33 on Fig. 2. Fig. 4 is an enlargedside elevation of the dog latching sleeve with a portion broken away toappear in vertical cross section. Fig. 5 is a. plan elevation of thesleeve. Fig. 6 is an enlarged vertical detailed sectional view of thelower portion of the drill showing the core catcher in the actuatedcondition and Fig. 7 is a transverse detailed sectional view takensubstantially as indicated by line 1-1 on Fig. 6.

The core drill provided by this invention includes, generally, an outerbarrel l carrying a bit head or cutter head I I, a normally inoperativecore catcher l2 in the head ii, an inner barrel l3 shiftable to operatethe core catcher l2, and releasable latchcontrolled means I4 rotatablysuspending the inner barrel l3 in a position where the core catcher isunactuated.

The outer barrel I0 is an elongate tubular structure provided at itsupper end with a sub l5. In the preferred form of the inventionillustrated the sub has a pin I6 screw threaded into the upper end ofthe barrel ID. A screw threaded pin I! may project from the upper end ofthe sub l for connecting the drill with a drill collar or other part ofa drilling string. The sub has a central longitudinal opening I8 forconducting the circulation fluid downwardly into the barrel I0. A sub orconnecting member I9 is provided on the lower end of the outer barrel l0and carries a bit head sub 20.

The bit head II comprises a body or shoe 2| screw threaded on the pin 22of the sub 20. The invention contemplates the employment of any suitableor desirable form of cutting means on the head I In the particular caseillustrated in the drawings the shoe 2| is provided withcircumferentially spaced blades 23 having reduced teeth 24 on theirlower inner parts. The blades 23 haveouter edges or reaming edges 25 andlower cutting edges 26.' The blades 23 operate to form an annular cut inthe earth formation and the teeth 24 operate in advance of the bladesand trim the core 0. The shoe 2| of the head I I has a vertical opening21 which receives the core C with suitable clearance. The opening 21 isshaped or formed to carry the core catcher [2 to receive the lower endof the inner barrel l3. The opening 21 is of enlarged diameterintermediate its ends and its enlarged portion is graduated in diameterhaving an upper inclined shoulder 28, an intermediate shoulder 29 whichmay be normal to the longitudinal axis of the drill and a lower shoulder39 which is inclined downwardly and inwardly. The wall portion of theopening 21 extending between the shoulders 29 and 30 is preferablyinclined downwardly and inwardly as illustrated in Figs. 1 and 6 of thedrawings. An annular recess or groove .3| is provided in the wall of theopening 21 at the lower end of the pin 22. Spaced longitudinal ports 32are provided in the wall of the shoe 2| and extend downwardly from the'groove 3| to the lower end of the shoe where they discharge adjacentthe blades 23.

The core catcher I2 is a feature of the present invention because it isnormally free: or out of active contact with the core C during thecoring operation and is adapted for positive actuation at the will ofthe operator or driller todependably recover and retain the core. Thecore catcher I2 is disposed in the enlarged portion of the opening 21and includes an annular or tubular body 33. The core catcher body 33 maybe sectional comprising two telescopically assembled ring sections.

The body 33 is free to turn or shift longitudinally in the opening 21 atwill. The major upper portion of the core catcher body 33 is disposedabove the shoulder 28 while the lower portion of the body 33 is adaptedto project below the shoulder 28 and the body 33 may have a graduated orstepped periphery. An annular space or opening 34 occurs between theopposing faces of the sections forming the body 33. Spaced transverseopenings 35 are provided in the wall of the body 33 and intersect theannular opening34.

In accordance with the invention core engaging dogs 36 are pivotallysupported in the openings 35 to project from the inner side of the body33. Pins 31 having their opposite end portions carried in the openings34 extend through openings in the dogsiG to pivotally support the dogsin the openings 35. The dogs 36 as held re-- tracted in the manner to behereinafter described normally project upwardly and inwardly intosuitable notches or recesses in the inner side of the body 33 and theactive ends of the dogs 36 are suitably sharpened. Notches or slots 38are provided in the outer or lower ends of the dogs 36 to carry springs39. The springs 39 surround the pins 31 and react against the body 33and the dogs 36 to urge the dogs downwardly and inwardly to their activecore engaging and retaining positions. In accordance with the inventionthe dogs 36 are normally held in their retracted positions and thereforethe springs 39 may be made 'as strong as possible or as strong asdesirable without danger of destroying the core 0. Cam parts 40 areprovided on the dogs 36 and are. adapted to project outwardly throughthe opencooperation causes the dogs 36 to be pivoted v downwardly andinwardly into the core C.

The core catcher |2 includes a sleeve 4| which normally latches or holdsthe dogs 36 inoperative or retracted. The sleeve 4| is positioned withinthe core catcher body 33 and is proportioned to freely receive or passthe core C. The sleeve 4| projects upwardly beyond the upper end of thebody 33 and its lower portion is provided with an external shoulder 42engageable by the lower end of the body 33 when the body is shifteddownwardly. Vertical or longitudinal slots 43 extend upwardly in thesleeve 4| from its lower end to make the lower portion of the sleeveflexible and contractible. Longitudinal windows or openings 44 extendupwardly in the sleeve 4| from its lower end. The dogs 36 are adapted topivot or swing downwardly and inwardly through the openings 44 when thecore catcher I2 is actuated or released for actuation. The active upperend portions of the dogs 36 normally engage the exterior of the sleeve4| above the openings 44 to prevent the dogs from pivoting through theopenings 44. The engagement of the spring urged dogs 36 with the sleeve4| aids in holding the sleeve in position.

The lower portions of the sleeve 4|. which are separated by the slots 43and the openings 44 are in the form of gripping slips S being providedon their inner sides with wickers or core engaging teeth 45. The outersurfaces 46 ofthe slips S are inclined downwardly and inwardly tocooperate with the inclined wall portion of the opening 21 and theshoulder 30 as will be hereinafter described. The slips S have upwardlyfacing shoulders 41 on their outer sides spaced below the shoulder 42.The shoulders 41 are engageable by the lower end of the core catcherbody 33 after the slips S have been actuated inwardly against the core.A spring ring 48 is arranged in a groove in the inner sides of the slipsS above the teeth 45 to urge the slips outwardly and aid in holding thesleeve 4| in position and in its normal uncontractedcondition. It is tobe particularly noted that the core catcher l2 including its sleeve 4|does not actively engage the core C during the drilling or coringoperation and, therefore, does not destroy or mutilate the core. I

The inner barrel I3 is arranged longitudinally in the outer barrel IIIto receive and hold the core C. The inner barrel |3 preferably has thinwalls to be light in weight and is spaced from the interior of the outerbarrel I0 to leave an annular the lower end portionof the inner barrelI3 and is rotatably received in the upper portion of the opening 21. Theinner barrel [3 is free to rotate or to remain stationary duringrotation of the drill and the collar- 5| is free to rotate and shiftlongitudinally in the opening 21. A hardened ring 52 may beprovided onthe upper end of the collar 5| to bear. upwardly against the lower endof the pin 22 when the engagement of the core C with the inner barrel |3tends to hold the inner barrel upwardly as the drill is fed into theformation. The opening in the collar 5| is enlarged at 53 to receive theprojecting upper portion of the sleeve 4| and the projectingupper endsof the retracted. dogs- 36$ Ports 54 extend through the collar 5| toconnect the passage 50 with the groove 3| so that the circulation fluidmay passdownwardly from the passage 58 to the collar 5| is normally freeof the core catcher body 33 as shown in Fig. 1 of the drawings but isadapted to bear downwardly against the upper end of the body 33 torelease or actuate the core catcher.

A valve is provided on the upper end of the inner barrel l3 to allowfluid to be displaced from the inner barrel as it receives the core. Thevalve may include a tubular cage or body 55 positioned within the upperend portion of the inner barrel. The valve body 55 ls preferablyreleasably or detachably connected with the inner barrel. In theparticular structure shown lugs 56 on the valve body 55 project intobayonet slots 51 in the wall of the inner barrel to connect the valvebody with the inner barrel. A valve seat 58 is screw threaded in thelower portion of the valve body 55 and a ball 59 is adapted to cooperatewith the seat to prevent the downflow of fluid through the valve. Theball 59 is retained against loss or displacement by a member 66 having aperforated web 6| extending across the mouth or upper end of the valvebody 55.

The latch controlled means |4 normally sus pends the inner barrel l3 ina position where the core catcher I2 is unactuated. In the preferredform of the invention the means I 4 rotatably suspends the inner barrelfrom its upper end so that it may float or rotate at will. The means I4includes a tubular member 65 slidable or shiftable longitudinally in theopening l8 of the sub l5. The upper end of the tubular'member 65 is opento the opening or passage l8 and ports 66 in the wall of the membercarry circulation fluid to the upper end of the passage 50. The lowerend portion of the tubularmember 65 is threaded and riveted or otherwisefixed to the member 60. The lower face of the tubular member 65 opposesthe upper end of the valve body 55. An upwardly facing shoulder 61 onthe member 60 opposes a downwardly facing shoulder 68 on the valve body55. The valve body 55 is rotatable on the member 60 between theshoulder61 and the lower end of the member 65 so that the members 60 and 65rotatably suspend the inner barrel.

' A latch I normally holds the tubular member 65 against downwardmovement and therefore holds the inner barrel l3 against downwardmovement and prevents actuation of the core catcher I 2. The latch I6 ispositioned within an opening II in the wall of the member 65 and ispivotally supported by a pin I2. The latch III has a downwardly facinghead or nose I3 for cooperating with the inclined lower wall of a grooveIt in the wall of the opening Hi. The groove I3 is preferably ntinuousor annular. A spring I normally urges the latch to the positionwhere itsnose I3 cooperates with the wall of the groove I4. The cooperation ofthe latch I0 with the groove I4 holds the parts in the position wherethe inner barrel i3 is suspended as illustrated in Fig. 1 of thedrawings where the lower end of its collar 5| is clear of the upper endof the core catcher body 33.

A comparatively heavy spring 16 may be arranged under compressionbetween a shoulder 'II on the pin I6 and a shoulder I3 on the member 65to urge the inner barrel I3 downwardly upon the release of the latch 16.The invention includes an object 30 adapted to be dropped through thedrilling string to release the latch 10. The object 86 may be in theform of a sphere or ball. The latch I0 isprovided with a lug 8| whichprojects inwardly into the longitudinal opening 82 of the member 65. Theball or object 86 isproportioned to fit the opening 82 rather closely toengage the lug BI and pivot the latch III to free the latch nose I3 fromthe wall of the groove I4. The object 80 is adapted to come to rest onthe web 6| where it does not interfere with the passage of the fluiddownwardly through the opening 82 and ports 66.

In operation the drill is attached to the lower end of an operatingstring of drill pipe and is rotated and fed downwardly in the well inthe usual manner. The parts of the tool are normally or initially in thepositions illustrated in Fig. l of the drawings. As described above, the

cooperation of the latch II! with the groove I4.

suspends the inner barrel I3, through the members 60 and 65, in aposition where the lower end of its collar 5| is clear of the upper endof the core catcher body 33. The sleeve 4| positioned within the corecatcher body 33 prevents the inward pivoting of the core catcher dogs36. The blades 23 with their teeth 24 operate to form an annular channelor bore in the earth formation and leave the core C which is received inThe circulation fluid is continuously pumped down through the drillingstring under pressure to flow through the openings l8 and 82 into thefluid passage 50 and from the passage through the ports 54 and groove 3|to finally discharge from the ports 32.

After a core of the desired length has been cut or formed the ball orobject 80 is dropped through the drilling string. The object 80 passesdownwardly through the opening l8 and enters the opening 82. During itspassage through the opening 82 the ball engages the lug 8| to pivot thelatch I0 to its released position. Upon the release of the latch fromthe groove I4 the inner barrel l3 moves downwardly under the influenceof the spring I6 and its own weight. Downward movement of the innerbarrel |3 brings the lower end of the collar 5| against the upper end ofthe core catcher body 33 causing the core catcher body to movedownwardly with the inner barrel. As the body 33 moves downwardly itslower end bears against the shoulder 42 to move the sleeve 4|downwardly. In this manner the inclined outer surfaces 46 of the slips Sare ,forced against the inclined shoulder 30 of the opening 21 so thatthe slips S are forced inwardly into the core C. After the sleeve 4|.andthe core catcher body 33 have moved downwardly a relatively shortdistance the lower end of the body 33 is disengaged from the shoulder 42of the inwardly flexed slips S. This allows the core catcher body 33 tomove downwardly relative to the sleeve 4| until the lower end of thebody 33 engages the shoulders 41. The engagement of the slips S with theshoulder 36 holds the sleeve 4| stationary during this movement or thebody 33.

The relative movement between the core catcher body 33 and the sleeve 4|brings the dogs 36 to positions where their springs ,39 pivot theminwardly. through the openings 44. The dogs 36 are thus made topenetrate or bite into the core C and the cam parts 40 may cooperatewith the shoulder 28 to further advance or pivot the dogs into the core.The cam parts 40 may engage the walls of the openings to stop or supportthe dogs in substantially horizontal core supporting positions.Following the release and actuation of the dogs 36 downward movement ofthe core catcher body 33 may be continued until its lower end engagesthe shoulder 29. The sleeve 4| is then caused to movedownwardly with thecore catcher body 33 sothat its slips S are eflectively forced inwardlytogrip the core through the cooperation of the surfaces 46 with theshoulder 30. In most instances the dogs 36 are effective in breakingfree and retaining the core. However, the additional engagement of theslips S with the core may aid in removing a hard core. After the innerbarrel i3 has moved downwardly as far as it will and the slips 8 haveengaged the core, raising of the tool may bring the dogs 36 against theupper ends of the openlugs 44 to increase the actuating or pivotingpressures on the dogs. The engagement of the slips S with the coretemporarily holds the ring 4| against movement allowing upward movementof the dogs 36 relative to the ring :to efiect this further actuation ofthe dogs 36.

Following the tripping and actuation of the core catcher I! the drill israised and brought to the surface and the core is removed from the innerbarrel l3. The core drill of the present invention is particularlyeffective and is operable to recover full sized unmutilated coresofearth formations of various characters. The core catcher i2 isnormally latched or held'in a fully contracted condition so that it doesnot cut away the core and may be positively actuated at the will of theoperator without manipulation of the drilling string. Accordingly, thedrill is operable to remove substantially the entire core from theapplication herein set forth, but wish to reserve to myself anyvariations or modifications that may appear to those skilled in the artor fall within the scope of the following claims.

Having described my invention, I claim:

1. In a core drill havinga barrel and a core forming cutting head, thecombination of a shiftable spring urged core recovering element, asleeve positioned in the element to hold the element inoperative andadapted to readily pass the core, and spring means for moving theelement out of engagement with the sleeve after the pas- 'sage of thecore through the element.

2. In a core drill having a barrel and a core forming cutting head, thecombination of an annular series of spring urged core recoveringelements, a member normally positioned within said series to hold theelements in a retracted position clear of the core, and means for movingthe elements out of engagement with the member including a shiftablepart normally urged into moving relation with the elements, and areleasable latch in the barrel holding the shiftable part againstmovement. 3. In a core drill having a barrel and a core forming cuttinghead, the combination of a spring urged core recovering element at thehead,amember at the head normally engaging the element to hold it in aretracted position clear of the core, and means for moving the elementout of engagement with the member including a shiftable part normallyurged into moving relation with the element, a releasable latch holdingthe shiftable part against movement, and an object to be passed throughthe drilling string to release the latch. 4

4. A core drill including a tubular body having cutting means on itslower end, two elements in the body related for relative verticalmovement, one a core recovering member, the other a latch part normallyholding the member in a retracted position clear of the core, aninnerbarrel for receiving the core and shiftable to effect relative movementbetween said elements to release the member for operation, andreleasable latch means normally holding the inner barrel against suchshifting.

' 5. A core drill including a tubular body having cutting means on itslower end, two relatively movable elements in the body, one a. springurged core recovering dog, the other a member normally holding the dogin a retracted position, an inner barrel for receiving the core andshiftable to effect relative movement between ,said elements, to releasethe dog for operation, and releasable latch controlled means normallyrotatably suspending the inner barrel and holding it against suchmovement. v

v6. A core drill including a tubular body having cutting means on itslower end, two, relatively movable elements in the body, one a springurged core recovering dog, the other a member normally holding the dogin a retracted position, an inner barrel for receiving the core andshiftable to effect relative movement between said elements to releasethe dog for operation, a spring for shifting the inner barrel, and alatch normally holding the inner barrel against such movement andreleasable by an object dropped through the drilling string.

7. A core drill including a tubular body having cutting means at itslower end, a normally inoperative core catcher in the body, an innerbarrel in the body for receiving the core and shiftable to actuate thecore catcher, a spring for shifting the inner barrel, a longitudinallyshiftable member having a rotatable connection with the inner barrel,and a latch holding the member against longitudinal movement andreleasable,

by an object passed into the drilling string.

8. A core drill including a tubular body having cutting means at itslower end, a normally inoperative core catcher in the body, an innerbarrel in the body for receiving the core and shiftable to actuate thecore catcher, a tubular member longitudinally shiftable in the upperportion. of the body and receiving the circulation fluid from thedrilling string, there being a port in the member conducting the fluidinto the body, a rotatable connection between the inner barrel andmember, a latch holding the member against movement to .suspend theinner barrel, and an object adapted to be droppedthrough the drill ingstring to release the latch and pass to a position clear ofthe portwithout interrupting relative to the body and the sleeve to free its dogfrom the sleeve.

10. A core drill including a tubular body having cutting means at itslower end, a core catcher shiftable in the body and comprising a springurged core engaging dog, a sleeve in the core catcher normally holdingthe dog retracted, means normally holding the sleeve against movement,an inner barrel in the body shiftable to move the core catcher to freeits dog from'the sleeve,'and means normally holding the inner barrelagainst shifting releasable under the control of the driller.

11. A core drill including a tubular body having cutting means at itslower end, a core catcher shiftable in the body and comprising a springurged core engaging dog, a sleeve in'the core catcher normally holdingthe dog retracted, a core gripping part on the sleeve operable byengagement with the body, yieldable means normally holding the sleeveagainst movement, and means for shifting the core catcher relative tothe sleeve to free the dog from the sleeve and then shifting the sleeveto actuate its gripping part.

12. A core drill including a tubular body having cutting means at itslower end, a core catcher sliiftable in the body and comprising a springurged core engaging dog, a sleeve in the core catcher normally holdingthe dog retracted, a core gripping part on the sleeve operable byengagement with the body, yieldable means normally holding the sleeveagainst movement,

normally spaced movement transmitting shoulders on the core catcher andsleeve, and means for shifting the core catcher to free its dog from thesleeve and then cause movement of the sleeve through cooperation of saidshoulders whereby the gripping part is actuated.

13. In a core drill having a tubular body, a shiftable tubular member inthe body, pivoted core retaining dogs on the member, springs urging thedogs inwardly, a sleeve within the tubular member normally holding thedogs retracted, the tubular member and sleeve being related for relativemovement, there being openings in the sleeve through which the dogspivot inwardly upon relative movement between the member and sleeve, andmeans for causing relative movement between the member and sleeve.

14. In a core drill having a tubular body, a shiftable tubular member inthe body, pivoted core retaining dogs on the member, springs urging thedogs inwardly, a sleeve within the tubular member normally holding thedogs retracted, the tubular member and sleeve being related for relativemovement, there being openings in the sleeve through which the dogspivot inwardly upon relative movement between the member and sleeve,core gripping slips on the sleeve operable by cooperation With the body,and means for causing relative movement between the member and sleeveand actuating movement of the slips against the body.

15. In a core drill having a tubular body, a shiftable tubular member inthe body, pivoted core retaining dogs on the member, springs urging thedogs inwardly, a sleeve within the tubular member normally holding thedogs retracted, the tubular member and sleeve being related for relativemovement, there being openings in the sleeve through which the dogspivot inwardly upon relative movement between the member and sleeve, thesleeve being longitudinally split to be contractible through contactwith the body, core gripping parts on the interior of the contractibleportion of the sleeve, and means for causing relative movement betweenthe member and sleeve to release the dogs and for moving the sleeve tocontract the same.

16. In a core drill having a tubular body, a shiftable tubular member inthe body, pivoted spring urged dogs on the member, a sleeve. in themember having both ends open to receive the core and normally holdingthe dogs retracted, and means limiting movement of the sleeve whereby itpasses downwardly over the core as the same is formed.

ALFRED C. CATLAND.

